Ranking Factors
There is only one ranking factor applied to speed which search engines take into account - it's server response time. At the same time the loading speed of a whole web-page which depends mostly on a time taken to download the static content indirectly influence other important points for search crawlers, such as:
- Pages per Session: the average number of pages viewed during a session on your website.
- Bounce Rate: the percent of visits that are single-page only (i.e. people who visit one page and leave).
- Average Session Duration: the average length of visitors' sessions.
- Active Actions: the number of active actions done by a single user on a webpage.
Usually a high bounce rate means that loading speed in not high enough and people are leaving your site (or a certain page) because they just quit waiting. For Google or Yandex this is a tell-tale sign that this site doesn't fit a user request so it's rank in search results should be lowered. With a CDN your users always get the content at high speed and are more likely to browse more pages on your site. This, in turn, will positively affect SEO results.
What you should bear in mind enabling CDN
- Your own website subdomains used for static content delivery has more value for Google, comparing to third-party domains. That's why we suggest using your own subdomain with a CDN (you can do it by simply creating a CNAME and pointing it to a CDN) You can learn more about CNAME records and how to use them in this article.
- When you publish your content on a CDN, you specify an origin source which will be the source of content for a CDN. If you set the main page of your website (site.com) as an origin source, all content including the whole pages of your content will be available at several URLs (for example at site.com, 1234567.r.worldcdn.net, cdn.site.com). It leads to duplicate content and negatively affects SEO.
What you need to do in order to avoid problems with SEO?
Move your static assets on a separate subdomain (for example static.site.com). The whole pages of your site shouldn't be accessible via this subdomain.
If such a division is not possible and the only available option is specifying your main page as an origin source for a CDN, please consider the following tips:
- Prevent your contents stored in CDN from indexing by search engines. You can do it in the Control Panel with the Web Crawlers Block option (It is active by default. In case you want to index the content stored in a CDN, uncheck this option).
- If you need search crawlers to index your content published on a CDN, but you still don't have an opportunity to move static files to the subdomain, you need to set up the rel="canonical" attribute in the <link>-tag to display your default (canonical) URL. Unfortunately, in most cases this method works only with Google.
- One more way is to configure the custom robots.txt for content stored in a CDN. This method allows indexation of cached content only for certain search crawlers. You can read more about in this article.